Conventionally, as proposed by the Patent Document 1 (PTL1), a driving assist apparatus for a vehicle, which carries out lane keep assist control and lane departure suppression control has been known. For example, the lane keep assist control assists a steering operation by a driver, by detecting white lines on right and left sides of a road with a camera sensor, setting up a target traveling line (for example, a central line which is in a center position of the right and left white lines) based on these right and left white lines, and giving steering assist torque to a steering mechanism such that a traveling position of a self-vehicle is maintained near the target traveling line.
On the other hand, the lane departure suppression control is control in which steering assist torque is given to a steering mechanism to assist a steering operation by a driver such that a self-vehicle does not deviate out of a traveling lane when the self-vehicle is likely to deviate out of the traveling lane (out of the white line). Although an apparatus disclosed in the Patent Document 1 (PTL1) informs a driver of a warning when a self-vehicle deviates out of a traveling lane, the one which gives a warning to a driver and offers steering operation assistance by giving steering assist torque, as mentioned above, has been known for these days.
An in-lane driving assist apparatus comprises a lane keep assist control part which is a function part to carry out the lane keep assist control and a lane departure suppression control part which is a function part to carry out the lane departure suppression control, and switches between the lane keep assist control and the lane departure suppression control depending on a predetermined switching condition, such as the traveling position of the self-vehicle with respect to the traveling lane, and performs the control.